An implantable medical device (“IMD”) is a medical device that is configured to be implanted within a patient anatomy and commonly employ one or more leads with electrodes that either receive or deliver voltage, current or other electromagnetic pulses (generally “energy”) from or to an organ or tissue for diagnostic or therapeutic purposes. In general, IMDs include a battery, electronic circuitry, such as a pulse generator and/or a microprocessor that is configured to handle RF communication with an external device as well as control patient therapy. The components of the IMD are hermetically sealed within a metal housing (generally referred to as the “can”).
IMDs are programmed by and transmit data to external devices controlled by physicians and/or the patient. The external devices communicate by forming wireless bi-directional communication links with the IMDs. Recently, these external devices may include commercial wireless devices such as tablet computers, smartphones, and the like. For example, a patient may have an IMD that communicates with a tablet computer used by a physician to receive data from and change the settings of the IMD. The tablet computer receives data from the IMD regarding the patient's physiological state (e.g., the IMD may transmit stored data or sensed physiological parameters). Based on the received data, the physician may adjust the operating parameters of the IMD using the tablet computer.
To initiate the communication link, the IMD and the external device perform a handshaking protocol. During the handshaking protocol, the IMD may have a predetermined timeframe to transmit an invitation data packet and to receive a connection request by the external device. The invitation packet may contain frequency synchronization information, address information, or the like. The external device may receive the invitation data packet and transmit the connection request using the connection specification protocol and data within the invitation data packet (e.g., frequency synchronization information, address information, and the like). If the IMD receives the connection request within the predetermined timeframe the IMD may establish a bi-directional communication link with the external device.
In order for the IMD to do both, transmit the invitation data packet and receive the connection request within the predetermined timeframe, the IMD may have to continually perform the handshaking protocol (e.g., transmit the invitation data packet) regardless of whether the external device is present. By continually transmitting the invitation data packet, the battery life of the IMD may decrease requiring replacement of the IMD. Consequently, there is a need of a method to change the performance of the handshaking protocol by the IMD depending on whether the external device is present or not.